The Federal Women Study is an active clinical protocol recruiting 360 federal employees and contractors (120 African-American, 120 African immigrant, 120 white) working in the Washington DC metropolitan area that aims to identify the earliest risk factors for diabetes and heart disease by race and ethnicity. To evaluate novel screening paradigms, we recently compared the diagnostic ability of two morphological features of the glucose curve (time to glucose peak and glucose curve)as prediabetes risk prediction tools. Using a multiple-sample 2hour oral glucose tolerance test (OGTT), we showed that the glucose peak parameter maximized the information gained from a single OGTT - without increasing the time commitment of the participants - and was a strong independent indicator of pancreatic beta cell function. This work was recognized nationally (oral presentation at Endocrine Society Annual meeting in 2017) and by media outlets and is E-published ahead of print (Clin Endocrino (Oxf). 2017;00:1-8. httpsL//doi.org/10.1111/cen.13416). Our findings support the need for larger validation studies of the time to glucose peak parameter, especially in communities with a combination of high population risk for diabetes and limited resources. The Federal Women nested study was designed to help unravel the complex association of race/ ethnicity, hepatic insulin resistance and the pathway to diabetes. This project evaluates the components of hepatic glucose production (gluconeogenesis and glycogenolysis) and the contribution of hepatic to total body insulin resistance by race and ethnicity. Eligible women (30 African descent and 30 white) who participate in the primary protocol (13-DK-0090) are being invited to participate in the nested study to measure glucose and fat metabolism and energy expenditure. Recruitment is underway and 43 of 60 women have completed our nested study, with additional participants scheduled in the coming months. A pre-specified interim analyses was performed when 50% of participants were recruited (n=34; 50% African-American, 15% African immigrant and 35% white; age:37(2), mean(SD); BMI:33(2) kg/m2). This analysis demonstrated a significant difference in fasting glucose concentrations and hepatic glucose production between African descent and white women. Therefore, recruitment is ongoing and we anticipate that this mechanistic approach to understanding the biology of health disparities in diabetes will provide necessary information for evaluating the utility of fasting hyperglycemia as an effective screening test for diabetes in the African diaspora.